When we look at efficient golf swings, we notice things such as simplicity, dynamics, and rhythm. When these attributes are apparent, the golfer is usually moving through very leveraged positions in the golf swing. One of the most important yet misunderstood moves in the golf swing is the start down or forward.
If an athlete has loaded into a sound position at the top of the backswing with pressure on the inside of the trail foot and the sternum over the back knee, he/she is poised to make a simple powerful move to start down. This move entails moving laterally towards the target with the lower body leading but does not mean that the sternum stays or falls back. Many times athletes are recovering from a reverse spine position where the upper body is leaning towards the target and they are forced to fall back in an effort to come into the ball with a more shallow path. Ideally, the first move down is forward getting pressure into the lead foot with the sternum following along, and putting the athlete into a position of leverage where he/she can rotate hard on top of the lead foot.
In the GEARS snapshot above the vertical line drawn through the body is a representation of this exact move. This golfer is starting to move forward and get pressure into the lead foot which will be a very leveraged position from which to rotate. If this move does not happen then leverage is lost and it will be very difficult for the golfer to control the contact point with the ground and compress the golf ball.